The invention relates to a one-piece armature housing.
Such an armature is known from the French patent application 2,266,069. In order to permit mounting of the closing wedge inside the housing, the latter exhibits the characteristic that, of the two connecting pipes between which the sliding wedge is to be disposed so as to form a seal, only one is equipped with a seating ring. The housing parts holding the seating ring, as well as the seating ring, reduce the flow cross section which is smaller than the nominal width of the armature. These components are missing at the opposite connecting pipe thereby making it possible to insert the sliding wedge in the housing. For the sliding wedge to maintain pressure against the seating ring, the pressure connection without a seating ring is provided with two inclines which are transverse to the flow direction and lie opposite one another. These cooperate with suitable protrusions on the sliding wedge to thus maintain pressure in the closed position. The inclines must have dimensions which, on the one hand, permit reliable pressing to be achieved and, on the other hand, permit passage of the sliding wedge and connection thereof to the driving spindle.
Since, for installation, the valving element must be smaller than the cross section of the openings in the couplings, the corresponding seat cross section is consequently relatively small and the ratio of coupling cross section of the armature housing to seat cross section exceedingly unfavorable. Taken in conjunction with the requisite protruding inclines, this results in a poor flow coefficient zeta.